Note 7 - Income Taxes - Reconciliation of Income Tax Rate (Details)	12 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Statutory federal income tax rate	21.00%	30.40%	35.00%
State income taxes, net of federal benefit	2.90%	2.40%	2.20%
Domestic manufacturing deduction benefit		(2.40%)	(3.00%)
Remeasurement of deferred taxes		(2.90%)
Other differences	(0.50%)	(0.40%)	0.10%
Effective income tax rate	23.40%	27.10%	34.30%